I have never heard that FR-2 would not hold up in ionic cleanliness testing and it makes no sense to me. The 600 SMD uses IPA/water mixture and the test duration is usually about 10-15 minutes at temperature <125 deg F. With all the other processes that the board has to withstand (corrosive fluxes, wave solder, etchants, etc, IPA/water seems pretty benign. I would check with your source for this information. It seems bogus to me. Larry Fisher Dexter Electronic Materials [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************